When playing as the monarch in one of the quests, you have to ask 3 of your servants to give you an honest opinion of how you're running the country. While they're all funny on their own, I found talking to the jester hilarious. Simply put, the jester recites a poem that is obviously more of an insult than anything. The monarch's response?
When holding court as a monarch, some of the petitions the citizens approach you with can get really amusing. Of note is a guy who asks the Monarch for permission to have a child. The positive option is to tell him he doesn't need your permission for something like that, and the negative one...
Monarch: Are you kidding? You want my permission to breed. You know what? No. Just because you asked me: no. You are banned from having children.
Also when holding court as a Monarch, a villager will come to request permission to burn the vulgar shrubbery his neighbor is sculpting, and regardless of how the Monarch replies, it's a rather easy request to forget. However, another villager might come later asking for funds to make a statue of the Monarch. If you say no, s/he will reply that they shall "go back to their other pastime of sculpting vulgar shrubbery".
If you use the Monarch to make an ally of the Crab Bandit, your reward is a fake mustache matching the bandit's.
The Wedding quest has a hilarious speech given by the best man/maid of honor at the end. It sometimes includes "Remember that timewe got caught up in that meat trade in Aarbyville?" It's even funnier if you just chose random Sims who didn't have an established friendship before the quest.